Current system architecture of typical web service systems is optimized vertically from the web browser to the Internet, web servers and storage servers so as to be scalable and highly available at lower less cost. Major web service providers develop their own storage software to manage data generated and used for their services in a homogeneous environment, but because of this, existing independent storage products cannot be used in or co-exist with their web service systems.
For example, in some web service systems, web servers create replicas of data by themselves. When new data is created by a user, a web server stores the data to one location and a replica of the data to another location. Because they typically use general-purpose PC servers for storing data and such PC servers do not have the capability to replicate data to other PC servers, web servers are required to create and manage replicas of data among multiple PC servers. Further, although dedicated storage system products are known that have data replication functions, they are much more costly to purchase and use in comparison to PC servers.
Further, vertical optimization or vertical integration carries the risk that, if new storage technologies become available that provide greater benefits when incorporated into a web service system, the system architecture must be changed to accommodate the new technologies as the web service system was not designed for using the new technologies. This change requires a lot of software development and which has a big impact on the cost.
In the above example, data is replicated by the web servers. If a new storage system becomes available that costs less than the current PC server used for storing data, web service providers may consider adopting the new storage system. Such a new storage system, for example, may be capable of replicating data among other storage systems, but because the web servers are replicating data by themselves, incorporating the data replication features in the storage system is redundant if not useless, unless the data replication program can be turned off or disabled in order to use this feature of the new storage system and remove unnecessary redundant data replication. Such changes may require additional developments and cost and so the web service providers may hesitate to adopt such new storage technologies for their vertically optimized systems.
The conventional web service system architecture would thus benefit from increased flexibility of utilizing new and different storage technologies in a heterogeneous environment.